Pittsburgh's tree trouble is no secret. In response to decades of deferred care, and repeated reductions in the city Forestry Division's budget, Carnegie Mellon's Heinz School conducted a study of Pittsburgh's urban forest in 1995. The findings, published as "Pittsburgh's Urban Forest: Planting For the Future," painted a bleak picture. It declared:

The Forestry Division removes four trees for each one planted.

An estimated 20 percent of trees that are planted in city rights of way do not survive five years.

The Forestry Division is critically understaffed, for the most part able to engage only in crisis management. In the 1970s, more than 30 people were employed in the Forestry Division; in 1995 there were 15, including two clerical staff.

A dozen years later, things have not improved. Now there are only 11 people, including one clerical person, to care for the trees along nearly 1,000 miles of city streets.

But "Planting for the Future" also offered remedies. One of the recommendations was to conduct a comprehensive inventory of Pittsburgh's street trees.

In 2005 the Pittsburgh Shade Tree Commission, in cooperation with the city's Department of Public Works, conducted a comprehensive inventory of the city's street trees and charted a management plan.

Based on inventory data, a seven-year program of activities including removals, pruning and new planting was prepared, along with a corresponding budget of funding needed to eliminate the backlog. The action plan budget includes only enough tree planting funding to begin to make up for the number of trees on the removal list.

The inventory revealed a total of 30,538 street trees. A previous sampling indicated a population of approximately 45,000 trees.

The total value of Pittsburgh's street tree population is $52 million, with an average value per tree $1,706.

3,185 trees were slated for removal because they were dead, or in very poor condition.

The genus Acer (maple) makes up 36 percent of the population. But diversity is imperative for a healthy urban forest; monocultures set the stage for devastation such as happened in the wake of Dutch elm disease.

A high percentage of Pittsburgh's street trees are only small or medium-sized. Without proactive maintenance, larger trees can prematurely end up on the removal list. The Pennsylvania Forest Association points out that too many communities make the mistake of planting new trees while neglecting older, more valuable trees, and that caring for existing trees should take priority over planting new ones.

A complete cost-benefit analysis of Pittsburgh's street tree data is under way using software recently developed by the U.S. Forest Service called STRATUM (Street Tree Resource Assessment Tool for Urban Managers). The analysis provides a dollar value indication of the environmental work performed by each tree. Preliminary results of Pittsburgh's forthcoming STRATUM study shows that every dollar we invest in planting and maintaining our street trees provides four dollars in benefits.

We are committed to preserving and enhancing one of Pittsburgh's most precious natural features. You can start to help in two simple ways:

Keep your street trees weeded, watered and properly mulched.

Become a "Tree Tender" volunteer: Attend our tree care workshops and seminars.